The present invention relates to a forming system for construction and, more particularly, to a system of forms for constructing walls, columns, piers and other structures.
The pouring of concrete walls is conventionally accomplished by erecting temporary wood or metal forms, pouring the concrete, leaving the forms in place until the concrete cures sufficiently, stripping the forms from the concrete, and erecting the forms in a new location. Unless a significant investment in additional forms is made, substantial costs in construction delays can be incurred as a result of waiting for the concrete to cure before stripping the forms, from the standpoint of both the availability of the forms for further use, and the accessibility of the concrete for further work, such as installing electrical outlets and fixtures. Furthermore, the stripping operation is costly in terms of time and money, and the forms must be replaced after several uses due to wear and tear. Moreover, when the forms are stripped away, the concrete has a rough finish having an appearance which is undesirable for many applications, and, thus, requires sandblasting, painting, covering or other treatment.
In other, related construction activity, a variety of structures are usually built using conventional concrete blocks which can be quickly produced by filling a standard concrete block mold box with concrete, applying compression and vibration, and sliding a concrete block form out of the mold. Although the block form must be allowed to harden, it becomes sufficiently firm to be slid out of the box in about 6 or 7 seconds. However, the assembly of conventional concrete blocks into a wall or similar structure is time consuming and requires a high level of skill. As a result, construction employing conventional concrete blocks is costly, with skilled labor accounting for 60%-70% of the cost of building a wall. In addition, there is little flexibility of design in a wall constructed of conventional concrete blocks, and it becomes difficult, if not impossible, to provide such a wall with insulation and convenient passages for plumbing, electrical lines and other utilities.
In order to overcome the drawbacks of reusable wood or metal forms and the limitations of conventional concrete block elements and the structures made from them, construction systems have been devised employing spaced panels made from thin shell concrete block elements in which the elements of one of the panels are tied by connecting members to corresponding elements in the spaced opposite panel. Some of these systems permit the inclusion of insulation and utility lines between the inner and outer panels, but suffer from a number of other limitations. The assembly of some of these wall systems is so complex that it is still very time consuming and requires considerable skill. In some cases, the installation of connecting members is difficult and some wall systems employ semi-rigid vertical reinforcing members, such as reinforcing rods, which tend to lean and interfere with the assembly of the thin block elements. Other wall systems use block elements having dimensions such that they cannot be accommodated in a conventional concrete block machine mold and, thus, require special molding machines, handling equipment and curing racks. Still other systems employ blocks with configurations such that they can not be slid out of a mold. As a consequence, they cannot be produced in 6 or 7 seconds, but instead must remain in the mold for a length of time on the order of 24 hours.